Effects of fatty acids on metabolism and cell growth of human colon cell lines of different transformation state.

Epidemiological studies suggest that high fish intake is associated with a decreased risk of colorectal cancer which has been linked to the high content of the n - 3 polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in some fish. In this study, two different cell lines are compared in relation to their response to EPA and DHA versus the plant derived PUFAs, linoleic acid (LA), gamma-linolenic acid (GLA), and alpha-linolenic acid (ALA) and to the ubiquitous arachidonic acid (ARA). The uptake of 100 microM of each fatty acid (FA) was determined using GC. The 4',6-diamidino-2-phenylindole assay for DNA quantification and the Cell-Titer-Blue assay were used to determine cell survival and metabolic activity at 2-72 h after treatment. All FAs were utilized more efficiently by the human colon adenoma cell line LT97 than by the adenocarcinoma cell line HT29. LT97 were more susceptible than HT29 cells to the growth inhibitory activities of all FAs except for DHA where both were equally sensitive. Inhibition of survival and metabolic activity by EPA and DHA increased with treatment time in both cell lines. ALA or GLA were less growth inhibitory than EPA or DHA and ARA had intermediary activity. The data show that the tested FAs are incorporated into colon cells. Furthermore, adenoma cells are more susceptible than the adenocarcinoma cells.